Thank you for the pointers Dr. Simmons-Ehrhardt. I will certainly take you up on your offer if I have additional questions. How much do you work with point clouds? Would there be any benefit to just working with a point cloud then meshing later in the process?
On Wednesday, September 2, 2020 at 6:40:40 PM UTC-7 [email protected] wrote: > Hi Eric, > > For processing scans in Meshlab, I align the scans and delete areas from > individual scans that weren't captured well--usually the outer edges of > each scan. You can remove these ugly areas before aligning as > well--sometimes it helps to align and then remove ugly areas from > individual scans. Save your edited scans along the way in case you mess up > (save edited, aligned, etc.). You don't have to edit if you're happy with > how your scans look--you can just align and proceed with the steps below. > > Once you have a set of aligned scans that look good, make sure you "Freeze > Current Matrix" of all layers--right-click on a layer to access this option > and also save these. Right-click on a layer again and apply "Flatten > Visible Layers"--this will merge all your layers into one (save as a new > PLY). To convert this to a mesh, I like using Filters --> Remeshing, > Simplification and Reconstruction --> Surface Reconstruction: Screened > Poisson. You will have to play around with the Reconstruction depth to see > what produces enough detail for you--I usually use 9 or 10. If Poisson > doesn't work, check the "Pre-clean" box or apply "Remove unreferenced > vertices" under the cleaning filter or you might also need to recompute > normals under the Normals filter. Once you get a mesh, apply a cleaning > step to remove any floaty bits that might have been produced--Filters --> > Cleaning --> Remove Isolated Pieces (wrt Diameter). You will get a > watertight mesh that you can export as a new PLY to use in SlicerMorph, R, > etc. You shouldn't have to apply any smoothing or hole-filling after > Poisson reconstruction, but you may want to decimate with Quadratic Edge > Collapse if needed as mentioned in previous replies. > > There are videos describing a scan processing pipeline on Meshlab's > youtube: https://www.youtube.com/user/MrPMeshLabTutorials that > demonstrate these filters. If your scans were collected with the same > settings, then your processing steps in Meshlab should produce consistent > models. Save along the way! Sometimes it might be easier to align scans > based on "regions" of your object rather than sticking to the scan > families--that's what I like about processing scans in Meshlab! > > I hope this helps. Feel free to email me with questions. > Terrie Simmons-Ehrhardt > > On Friday, August 28, 2020 at 8:27:25 PM UTC-4 [email protected] wrote: > >> Hello everyone, >> >> I'm just starting out in 3D GM and I'm really stuck when it comes to >> figuring out a workflow for producing 3D surface meshes that are de-noised >> without losing topological integrity, making them suitable for analysis. >> >> I've been using a NextEngine Ultra HD laser scanner for producing scans. >> I've then been moving the scans into Meshlab to to do everything else, from >> aligning and fusing to repairing and smoothing. I've come to view the >> number of filters in Meshlab to be both a blessing and a curse. I've also >> looked into MeshMixer, but everything seems to be black-boxed, and that >> make me a little uneasy. >> >> I'm also confused as to the order of steps. Should I fuse my scans and >> then clean and repair, or vice versa? What is the best way to de-noise? >> Should I smooth or remesh? In what order should I be applying filters? >> >> I'm hoping that someone here might be able to suggest a workflow to guide >> me through the process or direct me to some publications that can answer >> all of my questions. Also feel free to suggest some other 3D mesh >> applications that I'm likely not aware of. >> >> Any advice would be greatly appreciated. Thanks everyone! >> >> Best, >> Eric >> > -- You received this message because you are subscribed to the Google Groups "Morphmet" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/morphmet2/36d124ee-30eb-4526-ba72-2e49882a6276n%40googlegroups.com.
